Improvement in extension tables



PATENTED AUG 1 1871 lll Ill lll l|| lll lll lll IIIMI lll IIIIIIIIllJlllIl II rmnhnrmnnnnn AM, fworourHamAfH/c an, X'Wnsakus Moons.

UNITED STATEs JOHN J. MGKNIG-HT, OF TARRYTOWN, NEW YORK.

IMPROVEMENT IN EXTENSION TABLES.

Specication forming part of Letters Patent No. 117,659, dated August 1, 1871.

ions until the iirst has done its work, so that only one at a time is brought into gear. As each rack reaches the termination of its stroke it is held in an extended position by a spring-catch, which catch, when the ends of the table are to be brought together, is retracted automatically by the action V- of a iiange running between the two racks, as

hereinafter described.

Figurel is an under-side view of a table partially extended7 one of theleaves beingremoved. Fig. 2 is a longitudinal `section of the same on the line a' .1', Fig. l. Fig. 3 is a transverse section thereof on the line y y, Fig. 1. Fig. 4 is a perspective view of the connected pinions and flange, with the spring-catch and portions of the racks in connection with which they work.

A A1 A2 may represent sections of the frame of the table, supported upon legs B B in the customary manner, and C O the respective ends of the table-top. The frame is made in sections in the manner com mon in the construction of extension tables, and to the end sections are attached racks, D1 D2, which gear with pinions E1 and E2 formed or keyed upon a transverse shaft, G, working in suitable bearings in the main section A of the frame. The pinions E1 E2 have between them a disk or flange, F, which is of larger diameter than the said pinions, and, as the shaft rotates, moves freely in the space between the racks D1 D2. Near one end of the rack D2, which is mounted in the central section A2 of the frame, is a space, a2, without teeth,l adapted to permit the rotation of the pinion E2 without acting upon the rack D2 while the pinion E1 is acting upon the rack D1. H represents a spring-catch attached to the rack D2, and engaging behind the shoulder a1,-

near one end of the rack D1, when the latter has been moved into its extended position. The ofce of the ilan ge is to automatically release or retract this springcatch when the table is to be drawn in. For this purpose I employr a springswitch, I, attached to the free end of the springcatch H, and resting at its other end in close contact with the side of the rack D2, so that when the iiange F is moving in one direction the said switch will yield and permit it to pass; but when the ilan ge returns the switch will be so caught by the said liange as to draw it into close contact with the side of the rack D2, and thereby withdraw the spring-catch.

The table being in its retracted position, if it is desired to extend it the shaft G is, by means of a key, K, or other suitable appliance, rotated in the direction indicated by the arrow. The effect of this is to slide to the left the rack D1, and with it the end A1 of the table. During this time the pinion E2, being within the toothless spacea2, produces no effect upon the rack D2; but as soon as the rack D1 is extended to its limit the springcatch H engages in the notch or shoulder atthe end of said rack, and at the said time the continued rotation of the shaft, as the rack D1 has now stopped, carries the pinion E1 off this rack and the pinion E2 onto the cog portion of the rack D2, the iiange F passing between the side of the rack D2 and the free end of the switch I, which latter again springs into its closed position behind it. The effect Vof the continued movement of the pinion E2-is to slide out the Ycentral portion A2 of the frame, carrying with it the end A1, until the pinion reaches the end of the rack D2, when the table will be extended to its full limit if it be made with three sections only, as in the present illustration; but by means of additional pinions and sliding sections and racks, operated upon precisely the same principle, a table may be adapted to be extended to any desired length. When the table is to be retracted the shaft is turned in a reverse direction, the rst effect of which is to slide back the rack D2 and central section A2 by the action of the pinion E2, and as the ilange F approaches the spring-catch H it runs upon the switch I so as to retract the said spring-catch from its notch or shoulder in the rack D1 and release the said rack, so that when the pinion E2 reaches the toothless space a2 and the pinion E1 comes in gear with the rack D1, the latter will be drawn Within the section A1 of the frame and will bring the end sections A A1 of the table into close contact.

The racks, pinions, shaft, flan ge, and bearings may be made of eastron or other durable material.

I claim as my invention- As an improved apparatus for operating extension tables, the racks D D1, pinions E1 E2, springcatch H, switch I, and retracting-ange F, combned -and. .arranged substantially as and for the purposesset forth.

, JOHN J. MGKNIGHT. Witnesses:

FRANK H. WALGOTT, H. H. TOTTEN. 

